The objective of this research is to learn the detailed mechanism of action of various metal-activated and metalloenzymes. The purpose of studying a large number of enzymes is to seek general principles of enzymes chemistry which might be used ultimatley to control the rate and course of enzyme reactions in vivo and in vitro. When an enzyme is activated by or contains a paramagnetic metal ion (Mn, Co, Cu, Fe), or interacts with a paramagnetic substrate analog, structural, kinetic and thermodynamic information can be obtained about the immediate environment of the paramagentic center by electron spin resonance and by nuclear magentic resonance studies of the solvent, the substrates and the protein. The most useful NMR parameter is the longitudinal relaxation time (T1) of the nuclei of the substrate since rapid and accurate determinations of T1 permit distance calculations in solution. Improvements in the accuracy and speed of T1 determination have been made possible by the refinement of Fourier transform methods for measuring T1 and the development of methods for attenuating water signals. By studying the NMR parameters (including T1) of protons, phosphorus, carbon and other atoms of substrates enzymes will be investigated. The enzymes under investigation catalyze the transfer of nucleotidyl groups (DNA and RNA polymerases), pyrophosphoryl groups (PP-Rib-P synthetase) phosphoryl groups (pyruvate kinase, P-enolpyruvate carboxylase, adenylate kinase, succinyl CoA synthetase) hydride ions (alcohol dehydrogenase, malic enzyme) and catalyze reactions involving carbonyl polarization (biotin carboxylases, yeast aldolase). We are also improving the instrumentation and techniques for NMR studies of biological systems. Our finding of a unique substrate conformation on DNA polymerase and the presence of Zn in DNA polymerases provide a basis for the design of chemotherapeutic agents for malignant disease. A suicidal inactivator of DNA polymerases which we designed from mechanistic studies might be of value for further structural, chemotherapeutic and metabolic studies.